The present invention relates generally to rail inspection data processing systems and methods and, more particularly, to a rail inspection data processing system for processing and integrating data from both a magnetic induction sensor system and an ultrasonic sensor system.
Railroad rail inspection typically involves the use of magnetic induction sensors, ultrasonic sensors or both magnetic induction and ultrasonic sensors. Use of magnetic induction sensing involves the injection of a large direct current into the rail using two sets of contacts or brushes. Discontinuities in the railhead section cause a disturbance of the current flowing through the railhead between the contacts. The discontinuity is detected using a sensing head that responds to the accompanying magnetic field disturbance. Perturbations in the magnetic field around the railhead are detected as induced voltages in search coils in the sensing head. The induced voltages produce signal currents that may be processed and/or displayed to an operator.
Ultrasonic techniques typically use ultrasonic transducers mounted in pliable wheels that ride over the upper surface of the rail. These wheels are filled with a coupling fluid so that the transducers mounted inside can send ultrasonic signals into the rail. The return signals are processed and used to map the locations of flaws in the rail.
Not all rail defects are detectable by either the magnetic induction technique or the ultrasonic technique. Using a combination of the two methods greatly reduces the number of xe2x80x9cfalse callsxe2x80x9d (i.e., indications of a defect where such an indication is actually unwarranted). It is therefore desirable to conduct defect testing using both magnetic induction and ultrasonic techniques as complementary methods.
Combined usage of the two inspection techniques has generally been limited to separate identification of defects by the two systems. While processed data from both sensor systems may be displayed side-by-side to allow an operator to view results from both systems simultaneously, the data have not been integrated for use in a combined defect evaluation.
The present invention provides a data processing system that processes and integrates magnetic induction sensor data and ultrasonic sensor data and produces a combined inspection system defect file.
An illustrative aspect of the invention provides a data processing system for use in conjunction with a rail inspection system having a detection carriage with a plurality of sensor units configured to sense discontinuities in a rail of a railroad track as the detector carriage travels along the railroad track. The system comprises a data processing and recording computer connectable to the plurality of sensor units for receiving sensor data therefrom. At least one processor card may be included in the data processing and recording computer that includes at least one data object builder configured for building data objects using the sensor data from the plurality of sensor units. The at least one processor card may also include means for synchronizing the data objects with respect to location along the rail. The system may further comprise a defect detection module in the data processing and recording computer. The defect detection module is in communication with the at least one data object builder and is configured for using the data objects to determine rail locations having suspected defects.
Another aspect of the invention provides a method of identifying suspected rail defect locations that may be used in a rail inspection system having a data processing system in communication with a plurality of sensor units attached to a rail-traveling carriage. The sensor units are configured to sense discontinuities in a rail of a railroad track as the detector carriage travels along the railroad track. The method comprises propelling the detector carriage along the railroad track and generating periodic synchronization pulses as a function of distance from a fixed reference point on the track. Each synchronization pulse is assigned a synchronization pulse number. The method further comprises obtaining sensor data for a plurality of rail locations, each rail location having an associated synchronization pulse number. The sensor data are received at the data processing system. The method further comprises sampling the sensor data to create sensor data sets, each sensor data set including sensor data from one of the plurality of sensor units taken at one of the plurality of rail locations. The method still further comprises determining for each sensor data set whether the sensor data meets predetermined suspected defect criteria. Groups of spatially sequential data sets meeting the predetermined suspected defect criteria are then identified. Each group includes sensor data from only one of the plurality of sensor units. The data sets of each group collectively meet a set of predetermined object creation criteria. A data object is created from each group of spatially sequential data sets meeting the set of predetermined object creation criteria. The data object includes the synchronization pulse number associated with a selected one of the group of spatially sequential data sets. The method also comprises identifying suspected rail defects by applying defect detection rules to one or more data objects.